Since 1948, the M-648 radio receiver has been producing the Krasin Moscow Radio Plant.
Radio '' M-648 '' Moscow, 6 tubes (not counting the kenotron), 4 simultaneously operating circuits, 1948, superheterodyne, powered from the network.
The design is horizontal, the box is trimmed with valuable wood.
A large luminous scale, graduated in kilohertz with the names of the cities of the USSR, occupies the right half of the front side of the box.
At the top of the scale is the setting indicator.
Under the scale are the receiver control knobs.
The left knob controls the volume with the mains switch, the second tone control, the third setting and the fourth - range switch.
To indicate the range on which the receiver is currently operating, in the lower right corner of the scale there is a window behind which luminous labels with the name of the ranges move.
The left half of the front side of the receiver box, where the loudspeaker is placed, is tightened with a silk decorative cloth.
The antenna, ground, and adapter are connected from the back of the receiver.
Adapter sockets are automatic: plugging the adapter cord into the sockets terminates the RF part of the receiver.
Switching the voltage of the mains is carried out by moving the pads on the cover of the power transformer.
Unlike class 2 superheterodynes manufactured by our industry, the low-frequency amplifier of the M-648 radio receiver gives a lot of gain, which makes it possible to use an electromagnetic adapter to play gramophone records.
Frequency ranges: LW 150 ... 410 kHz, CB 525 ... 1500 kHz, HF survey 4 ... 12.3 MHz, KV-1 11.5 ... 12.4 MHz., KV-2 15.
..16.1 MHz.
Sensitivity in LW, MW ranges of 150 ... 200 μV, HF 300 μV.
Adjacent Channel Selectivity 26 dB.
The rated output power is 1.5 watts.
The range of reproduced frequencies is 100 ... 5000 Hz.
Power consumption 75 watts.